1. Field of the Invention
The present invention relates generally to anti-theft devices for automobiles, and more particularly, to an apparatus for preventing theft of the automobile by opening tile ignition circuit.
2. Description of the Prior Art
Automobile theft is a common crime, and many innovations have been developed to counter auto theft. In this respect, there are a number of situations in which auto theft commonly take place. In one situation, the automobile is unattended. In this case, the thief breaks into the automobile, shunts the ignition switch, and drives away. In another situation, while the legitimate driver is present, the thief hijacks the automobile. In this case, the keys are already in the ignition, and the thief does not need to perform any actions on the electrical circuitry of the automobile.
The following U.S. patents disclose a number of such anti-theft innovations: U.S. Pat. Nos. 3,824,403; 4,762,198; 4,792,792; 4,958,142; and 5,061,915.
More specifically, U.S. Pat. No. 3,824,403 discloses a power control circuit which operates to enable the start-up of a vehicle engine in response to a predetermined sequence of events such as depressing the brake pedal and actuating the ignition switch within a predetermined period of time. This device does not appear to have a provision for stopping an automobile engine once it has been started; that is, this device will not thwart a car hijacking or "carjacking". In this respect, it would be desirable if an anti-theft device for an automobile were provided which help prevent an automobile hijacking.
Another problem associated with the device in U.S. Pat. No. 3,824,403 is the requirement that a specific sequence of events take place in order for the automobile to be started. In certain situations, such a device may prove to cause great inconvenience. For example, when a person leaves the automobile with a parking attendant at a parking garage, the parking attendant will not know how to restart the automobile when the patron returns. In this respect, it would be desirable if an anti-theft device for an automobile were provided which did not depend upon a sequence of events in order for the automobile to be started.
U.S. Pat. No. 4,762,198 discloses a vehicle anti-theft system that employs an auxiliary switch that is interposed in the ignition controlling circuit between the main key switch and the ignition starting unit. The auxiliary switch is formed with a normally open single pole switch. The switch is provided with a separate probe which is insertable in the entrance tube of the switch structure to close the switch contacts. The switch is hidden within a decorative feature of a wall in the vehicle. A number of problems are associated with this type of device. For one thing, the separate probe may be lost or forgotten. If so, the automobile would be inoperable. In addition, such a device could not thwart an automobile hijacking. If a hijacker commandeers the automobile, the legitimate automobile operator would be at high risk if the operator disabled the automobile in the presence of the hijacker. In this respect, it would be desirable if an anti-theft device for an automobile were provided which thwarted a successful automobile hijacking without subjecting the legitimate operator to a high risk situation in which the automobile became disabled when both the hijacker and the legitimate operator were both present at the automobile at the same time.
U.S. Pat. No. 4,792,792 discloses an anti-theft system for an automobile in which a relay and two single-pole-single-throw switches are arranged in a manner such that, with attempted theft, the engine is deactivated, the horn sounds, and the headlights are turned on. A problem associated with this system is that two switches must be actuated. Such a system would not readily be usable when a parking attendant takes over control of the automobile at a parking garage. Moreover, if a long length of time elapses before the such an automobile is abandoned by a thief and recovered by the legitimate operator, the automobile battery may run down due to being drained by the headlights and horn. In this respect, it would be desirable if an anti-theft device for an automobile were provided which did not drain the automobile battery with headlight and horn usage when the automobile is abandoned by a thief.
U.S. Pat. No. 4,958,142 discloses an automobile theft deterrent system which employs two alarm systems. When a first alarm system operates, the second alarm system, under timer control, follows by spraying a would be thief with a pressurized, non-toxic, and non-corrosive irritant. In addition a siren or loudspeaker is also actuated by the second alarm system. This is a complex anti-theft system requiring two alarm systems. Moreover, if a thief is in any way harmed by being exposed to an irritant, in this litigious society, even a thief may bring a civil suit for damages against the owner of the automobile. In this respect, it would be desirable if an anti-theft device for an automobile were provided which did not employ any chemical irritants to be applied to a would be thief.
U.S. Pat. No. 5,061,915 discloses an anti-theft system for an automobile which includes a complex arrangement of interrelated relays and switches. The system is so complex that it is designed so that an operator can practice a sequence of disarming steps before actually using the invention in its intended way. In this respect, it would be desirable if an anti-theft device for an automobile were provided which is simple in operation and does need carrying out a complex series of arming or disarming steps.
Additional features would be desired in an anti-theft device for an automobile. A switch for enabling or disabling the automobile's ignition system should be easy to operate with a person's finger or fingers. The switch for enabling or disabling the automobile's ignition system may be concealed from immediate view by a driver as the driver is seated behind the steering wheel. By being concealed, it would be very difficult for a thief to locate it.
If an automobile is hijacked, the legitimate driver should be able to surreptitiously actuate the anti-theft device without letting the thief be aware of the actuation.
The desired automobile anti-theft device should enable a hijacker to be able to take over the automobile and drive away for a limited period of time, at which the automobile engine is disabled and the automobile ceases to operate. More specifically, the automobile should be enabled for a predetermined period of time after actuation of the hidden disabling device. This mode of operation will deter the thief from attacking the legitimate driver. Such danger to the legitimate driver would have a greater tendency to occur if the thief receives resistance from the legitimate driver or if an alarm sounds while the thief is in the presence of the legitimate driver as an alarm is sounded or as the automobile is disabled.
To make it even more difficult for a thief to successfully carry out an automobile hijacking, it may be desirable to provide a second hidden switch that is required to be actuated in order for the automobile ignition system to be enabled. If the second hidden switch is not actuated, then the automobile will not operate after the predetermined delay time period expires.
The time delay until disablement of the automobile should be an adjustable feature of an automobile anti-theft switch. Some persons may fear that if the time delay is too short, the automobile will become disabled while the thief is uncomfortably close to the legitimate driver. Another person may be more concerned that the thief not be able to drive the automobile too far before it becomes disabled. Such choices should be in the control of the user of the device.
Thus, while the foregoing body of prior art indicates it to be well known to use automobile anti-theft devices, the prior art described above does not teach or suggest an automobile anti-theft switch which has the following combination of desirable features: (1) helps prevent a successful automobile hijacking; (2) does not depend upon a special, unconventional sequence of events in order for the automobile to be started; (3) thwarts a successful automobile hijacking without subjecting the legitimate operator to a high risk situation in which the automobile becomes disabled when both the hijacker and the legitimate operator are present at the automobile at the same time; (4) does not drain the automobile battery with headlight and horn usage when the automobile is abandoned by a thief; (5) does not employ any chemical irritants to be applied to a would be thief; (6) is simple in operation and does need carrying out a complex series of arming or disarming steps; (7) is easy to operate with a person's finger or fingers; (8) is concealed from immediate view by a driver as the driver is seated behind the steering wheel; (9) can be actuated surreptitiously by the legitimate driver without letting the thief be aware of the actuation; (10) enables a hijacker to take over the automobile and drive away for a limited period of time, after which the automobile engine is disabled and the automobile ceases to operate; (11) provides a second hidden switch that is required to be actuated in order for the automobile ignition system to be enabled; and (12) has an adjustable time delay until disablement of the automobile takes place. The foregoing desired characteristics are provided by the unique automobile anti-theft switch of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.